Worcester WR 325 BF User guide

---~ ~ ~ORCESTER------.
Bosch Thermotechnik
WR3l5 BF
Gas Fired Multipoint
Water Heater
INSTALLATION AND
SERVICING INSTRUCTIONS
GC NUMBER 52 311 01
For yo ur safe ty -if you smell gas:
3. Do not operate any electrical sw1tches
1. Turn off the ap p liance
4. Extinguish all naked flames
2. Open all wi ndows and doors
5. contact t he loca l Gas Reg i on immediat el y
Thisapp
li ance con forms to Europea nStandard EN 26.
llis thel
aw that all gas app li ancesare installed by competent perso ns.
The fo ll owing instructions should be read car efu ll y as the manufacturer cannot be he ld
responsi
ble for any damage to property, perso ns or anima ls caused by in correct insta ll ation
oroperation ofthe applian
ce .
It iSrecommended that the appliance be serviced annually by a competent pe rs on or the
l
oca l Gas Region.
The Users Instructions should be handed to the user and the function and operation of the
app
li ance explained .

( .
Contents
1. In stallati on Regulations ... ........ ... .... ... ............ ... .... ..• ..... . Page 2
2. Ge ne ral Information .... ...... Page 2
3. Techn i cal Data .. .... . Page 5
4. Siting the Appliance ...... .... ........ .. ........ ...... .... .. ...... .. ...... PageS
3. Siti ng the Flue Term inal . .... . Page 5
6. Air Sup ply .... Page 6
.1.Installation Regulations
1. 1 Gas Safety (Installation and use) Regulat i ons 1984: · All gas
appliances must be installed by a competent person in
accordance
with the ab ov e regulations. Failure to install
appliances correctly could lead to prosecution .
1.2 The manuf acturer's no t es must not be taken, in any way . as
overriding stat ut ory ob li gations .
1.3
The compliance W1th a British Standard does n ot. of itself.
confer immunity from legal obligations. In particular the
in sta ll ation of t his appliance mus t be in accordance with the
releva nt requireme nts ofthe Gas Safety ( Ins tallation and use)
Regulat ions1 984 { as amended), local Building Regulations, Buildin g
Standards {Scotland) {Consolidation), byelaws of the l ocal Water
Company and Hea lth and Salety Document No. 635 ( Elec tricity at
Work Regu l at i ons 1989) . It should be in accordance with the
re levan t recommendations ofthe foll ow i ng British Standards .
BS 6 79 8:1987 Specification for Installation of gas fired hot water
boilers of ra t ed input note xceeding 60 kW.
BS 5546:1990 Installation of gas hot water supplies for domest ic
pur
po ses .
BS 5440:1:1990 Flues and ventilation lor gas appliances or rated
input not exceed i ng 60 kW:Fl ues .
BS 5440:2 :1 989 Flues and ventilation for gas appliances of rated
inputnot exceed i ng 60 kW :A •r Supply .
BS 6891:1988 Installation of low pressure gas pipework
installati
ons up to 28 mm (R 1).
1.4
To ensure that the installation will perform to the highest
stan
dards. the sy s tem and compone nts shou ld con form to any
other relevan t British Standards in addition to those menti oned
in the instru cti ons.
2. General Information
2.1 This appliance is available for use withnatural gas .
When installing the appliance for use with natural gas. please
check 10 digit number on carton to ensure that the correct
appliance ha s been specified. The 10 digit number for a natural
gas appliance is7 702 340 006.
2.2 This appliance is available lor use wi th lPG.
When installing the app li ance for use with LPG , please check 10
digitn umbe r on carton to ens ure that the correct app lian ce has
bee n specified.
The 10 digit number for an lPG app li ance is 7 702 440 007 .
2.3 T his appliance is not suitable f or external ins tallatio n.
2.4 The appliance is set to provide a maxi mum output of 21.4
kW and a minimum output of 7 kW.
2.5 T he appliance has a permanent p il ot.
2
7. Gas Supp ly .... .... .... .... .. ...... .. ..... .... .. .. .... .... .... .... .... .... ...... Page 6
8. Installation ... .... ... Page 6
9. Commissioning .... .. Page 7
10. Inspection and Serv i cing .. ............ .... .... .. ..... .. ............ ... P age 8
11.
Replacement of ?arts . ...... Page 9
12 . Fault Finding.. .... . Page 10
13. Short Parts list .... .. .... ...... .. ...... .... .... ... ............ ...... .. ...... . Page 10
2.6 PRINCIPLE APPLIANCE COMPONENTS
Al ow the rmal capaci ty Gas to Water hea t exchanger .
A
sta i nless steel main gas burner.
A
gas section.
A water section .
A thermoe lectric safety valve .
2.7 PACKING
The appliance and flue components are packed In separate
cartons .
2.8 GENERAL INSTALLATION
If the app li ance is to be fitted into a compartment. the
compartment must conform to
the re qui rements of BS
6798:1 987 : Section 6.
The specified ventilation openings made into a waH or
compartment doormust not be obstruct ed .
Do notp lace anything on top of the appliance.
The clearances specified for servic ing must be mainta in ed .
2.9 FLUE
The appliance h as a room·sealed balanced flue sys t em to t he
rear .
The standard R ue assemb ly will accommodate a wall th i ckness
of between 260 mm and 430 mm . The 10 digit code number for
the stan dard Rue assemb ly is 7 709 000 423 .
A short flue assemb ly is ava il able and will accommodate a wall
thickness of be t ween 100 mm and 1 50 rmn. T he 10 digit code
number lor the short flue assembly is 7 709 000 425.
An ex tended flue assemb ly is ava il able and will accommodate a
wall thick ness of betwee n 410 mm and 570 mrn . The 10 dig it
code numbe r for the ex t ended flue assembly is7 709 000 424 .
2.10 FACILITY TO FIT A S POUT AND I NTE GRAL TAP KIT
T he app li ance has the facility for a spou t and integral tap kit to
be fitted for oversink installation. If this type of installation is
requ i red ,pl ease order the fo llowing components as necessary:
l ~ tegr al l<lp kit
!i ncorporating ho : and co ldt aps and handles)
7709000406
Chromeplatedswil'elspout- 150mmle ngth 7 709000041
C hr ome plated swil' cl spout - 2SO mm length 7709000042
Ch 10me plated SWil'~l spout - 350 mm length
770 9000043

Fig. 1. Appli ance water flow diagram
1. Heat exchange r
2. Pi lot gas pipe
3. Gas inje ct or noule
4.
Measu ri ng point
6. Valve spring
7. l
arge gas va l ve
8. Pi l ot gas filter
9.
Pi l ot gas valve
10. Main gas valve
Hot
Water Cold
Water
11 .
12 .
13.
14.
15.
16 .
17 .
18 .
19 .
20 .
KEY TO C OM P ONE NT S
Pi l ot gas valve stem
2 1.
Water strainer
Pi l ot gas button
22 . Hot water connecting pi pe
Gas c on trol slide 23. Cold wa t er C<lnne c ting pipe
Piezo igniter
24 . Volumetric w at er governor
Gas fi lter 25. Water R ow selector
Magnetic un it 26. Rel i ef valve
Slow - ign i tion valve
27 . Correcting screw for mini mum
Venturi
wa terflow
Measuring point
2 8. Di a phr a gm
Gas inlet
2 9. B low ·off valve
3

Fig. 2. App li ance components
KEY TO COMPONEN TS
1. He at exchanger
2. Pilot gas pi pe
13. Gas cont rol sl ide
1 4. Piezo igniter
' 20 . Gas inl et- downward facing
22. H ot water conne c ting pipe- rear fa cing, left-hand sid e
23 . Col d water connecting pi pe - rear facing, right-hand side
25 . Water flow selector
' The gas inlet is si tuated towards the rear of the appl i ance .
30. Flue hood
31 . Combustion chamber seal
32. Main gas burner
33. Pilot assembly
34. Drain valve
35. Ga s se ct i on
36 . Water section
Do not confuse with the spout connection which is part of the bra ss housing.
4

3. Technical Data
'
TABLE 1 - GENERAL TABLE 2- FLUE DETAILS
Natura) Gas
LPG Wall hole si ze- width 224 mm (9in.)
Minimum rated ou r put 7kW 7 kW
Wa ll hole size- height 326 mm ( 13 in.)
Maximum
rated output
21.4 kW
21.4kW
Rated input 25 .5 kW 25 .5 kW
Ga s rate (m aximum) 2.7 m>/hr 2.0m> /h r
Number of in jectors 14 14
Injector diame ter 1 .1 0m m 0.74 mm
Standard flue- min imum l ength
260 mm ( 10.4 in .)
Standard fl ue -maximum length 4 30 mm ( 17 .2 in.)
Sho rt fl ue- minimum l ength 1 00 mm (4i n.)
Sho rt flue- max imum length 150 mm (6in.)
Ex t ended flue -min imum l ength
410 mm ( 16.4 in. )
Ex t ended flue -maximum le ngth 570 mm ( 22 .8 i n.)
Pil otinjector marking 5 49
Burner pr e ssure 17 mbar 27 mbar
Heig ht 755mm
755 mm
Width 40 0 mm 400mm
D ep th
22 0m m 220mm
D ry we ight 16 kg 16 kg
Ga s con ne ction f\c h
Rc '12
Hot / cold wat er connettions
15 mm copper 15mmcopper
TABLE 3 -PERF ORMANCE
Maxtmum col dwater supply inlet pres s ure
12 bar (180 p.s .i. )
Minimum cold water supply i nlet pressure tooperate the appliance
0.1bar(1 .5 p.s .i .)
Minimum co ld water supply i nl et press u re for maximum domes r ic hot water flow 1.0 bar (1 5 p.s. i. )
D
omestic hot water de li very with temperJture control knob fu llyantl cloc k wise 4to 12.3 1it res / mlnute at
25 °C temperature ri se
Domestic hot water de li very wi th temperature contro l kno b fully clockwise 2 to 6.1 lit res /minute at
'
4. Siting the Appliance
4.1 T he applian ce ma y be installed in any room which has an
ap p rop riate ou t side wall .
4.2
The app li ance is no t su itablefor external ins ta ll a ti on .
4.3 T
he ap pliance does no t require any sp ec ial wall protectio n.
4.4 T he wall must be capab le of supporting the weight of the
app
li ance . See Technical Data- Ta ble 1.
4.5 If the appliance is to be fitted in a timber fr ame d building,
re f er to the Br itish Gas Pub ii CJtion ' Gu i de for gas insta llations in
limber f
ramed hous i ng •.
4.6 The following cl earances must be available for installation
an dfor s erv i ci ng:
Ab ove SOmm
In front 60 0 mm
Be low 15 0mm
Right ha nd side 10rnm
Left hand sid e 10mm
4.7 Theapplian ce ca n beinstalled in acu pboa rd used fo r airing
cloth
es provided that t he requirements of SS 6798 and SS
5440 :2 are strictly followed.
4.8 The airing spa ce must be separated from the applian ce
spac e by a perforated non·combustlble partition. Expanded
metal or rigid wire
mesh are acceptable provided that themajor
dimension is Jess than 13mm. See BS6798:1987.
5
50°C tempe rat ur eri se
4.9 No combust i ble surface mustbe wi thin 75mm of the cas i ng .
See BS 476:4.
4.1o The
dts t ance between the I nne r face of a cu pboa rd door
and the cab i net front should not be l ess than 75 mm.
5. Siting the Flue Terminal
See Fig . 3.
5.1 The flue must be installed as specified in BS 5440:Part 1.
5.2 The termin
al must not cause an obstruc ti on nor t he
disc harg e cause a nu i san ce.
5.3 Ifthe termi nal is fitted wit hi n850 mm of apl asti cor pa inted
gutter or within 450 mm of painted eaves then an aluminium
s
hie ld at leas t 750 mm l ong shou ld be fitted to the un derside of
the gutter orpainted surface .
5.4
If a termin al is fitted less than 2 metres above a surfa ce to
which
peop le have access then agu ard mus t be fitted.
5.5
The terminal guard mu st be evenly spaced abou t the flue
terminal and fi xed to the wan u si ng plated screws .
5.6 In certain weather co nditi ons a terminal may steam and
siting whe rethis cou ld ca u se a nuisance shou ldbe avoided.
5.7 lll ke care to ensure that combus ti on produc ts do no t enter
ven tilated r oo f voids.

~. 3. Siting of the fl ue terminal.
I ~INIMUM SITING DIMENSIONS FOR POSITIONING THE BAlANCED
FlUE TERMINAl
I TERMINAl POSITION
r A• dI!eelly below an Openab!e WlndO'.V Or
othtt opeoni"'i t g air bnck.
a Bt~oY.· tLJUffl. soil pipes or dra:il'l ptpes
c .. Bciowe.r.n
MIN. D ISTAN CE
1<.00mm(60.rt)
JOO mm 1121tlJ
JOO mm 112lll.J
600mmt24 tnJ
7Smm(311l.)
600 mm (24 tn.J
300 mm (121n.)
600mm(2.4 in)
600mm(2,d in)
A
6. Air Supply
6.1 The appliance does not require a separate vent for
combustion atr.
6.2 lns1allatlons on cupboards or compartments require
permanent vents
for cooling purposes (one at high level and one
at
low level) either dtrect to outside air or to a room. Both vents
must pass to the same room or be on the same wall
to the
o utside air.
6.3 There must be sufficie nt clearance around the appliance to
allow proper circula ti on of ventil~tlon air. The cl ea ra nces
required
for Installation and servicing will normally beadequate
for ventilation
6.4 The mmlmum free areas required aregiven below.
Position of Air from Air direct
air vents the
room from outside
H1gh Level 270cm'. t35 em'.
(42 in '.)
121 ln'J
low Level 270 cm '. 135 em'.
(42 in '.) (21 in ' .)
6.5 Refer to BS 6798 and SS 5440:2 for additional Information.
7. Gas Supply
The appilance requires 2.7 m3 fh r (95.4 ft3fhr) of gas. The gas
meter and supply pipes must be capable of supplyi ng this
quantity of gas in addition to
the demand from a ny other
appliances being ~rved. T he fo llowin g table gives an In dica tion
of limiting gas pipe lengths and the allowance to be made for
fittings Refer 10 BS 6891 fo rfurther in for mation
The meier governor should deliver a dynamic pressure of 20
mbar (8 in w.g.)at the appliance.
The complete tnstallallon. includtng
the gas meter, must be
tested lorsoundnessand purged.
Refer to BS 6891 .
Agas servtce cock must be fitted
before each apphance. a gas
service cock
Is supplied with every natural gas appliance (not
supplied
w1th LPG model).
Important: If the 2 7m'/h r gas ra te to th e app li ance ca n no t be
reached. th e specified hot water condi ti ons will not beachieved.
This could resu lt In customer complaints. Always ensu re that the
ga s supply IS adequate.
6
o- Wow blkonlrs or c.lr port ,oo{
E- '-wrtr.oldr.wlpip<sandsol~
r- from lnlemal or external comers
G- Aboo.'t around. roof 0! bakony leo.'d
Jl ... From a $Urface facu-.g:a termmill.
I F'rom ~termina l facing a termmal
J f'rom M opel'l ing tna (ar port (e . .g. door
window) in to dwe-lling
K- ~rUclll l y !rom It terminal on the same
wall
L- uonz.ontally from a:enninal on the 'l.~rnt
W.tll
M From door. w~~Miow or a:r \'ffit 1iC.h~
~- .. po$$ibl<l
TOTAl LENGTH OF
GAS SUPPLY PIPE (metres)
3 I 6 I 9
Gas Discharge Rate (ml/h)
2.9 -
..
8.7 5.8 4.6
18.0 12.0 9.4
1200m m (47i n. )
1SODmm(60in.)
300mm(12 in)
J00mm(12n)
Pipe
Diameter
(mm)
15
22
28
No te : Eac h filli ng used in the gas line from the meter is
equivalent to a le ngth of straight p ip e which must be added to
th
estraight pipe le ngth to give the towIlength.
i.e. Elbow • 0.5 metres, Tee=O.S metres. 90' bend=0.3 metres.
8. Installation
T he insta ll ation must becarri ed o ut by competentpersons.
On delivery, check to make su re that the packaging has not been
damaged If there is evidence of damage. contact your supplier
immediately
Check the 10 dtgtt code number on the appliance carton to
ensure that the correct appliance
for the gas supply has been
supplied
Thecode number for a naturalgasappliance IS 7702 340 006.
The code number for an LPG appliance is 7702 440 007.
Before commencing work. check that the correct flue kit has
been supplied. There are three different telescopic flue kits
available forvarious wall thickne sses.
(Sec Thchn l ca l Data- "lllbie 2)
8.1 FLUE KITINST AL LA TION
Refer to Oue kit in stallation instructions which are packed inside
the nue
kit carton.
8.2 APPLIANCE INSTALLATION
(a) Unpack the applianceand takecare to remove themstallation
kit which IS packed ontopofthe polystyrene packmg.
The installation kit consistsofthe followmg
One gas serv1ce cock (not supp li ed wtth LPG model)
One co ld water iso lating cock co mplete with ftbre washer
One hot water outlet complete with fibre washer
1\No 15 mmx '12 in. SS P female copper com press ion fittings

(b ) Lay the appliQnce on Its back and pull off the Tem p erature
Conlro l Kno b.
(c) Unscrew the plastic Tempe rature Cont ro l Kn ob housing .
(d) Remove the four casing screw covers Take out t he four
casing fixing screws and lift the casing clear.
(e) Remove the collector hood from the appli ance bysl acken ing
the two fixing screws and hning the hood dear.
(Q l.ift the appliance on to the two mounting studs which are
part of the flue k1t assembly and fix on position using the two
slotted nuts supplied.
If required, there are fixing holes Situated on the appliance back
plate Mark the hxmg hole pos1t1ons on the wall. Remove the
appl1ance. Onll and plug the wall and then re·fit the appliance.
(g) Push the flue gas connecting duct mto the flue duct stub in
th<' balanced Oue assembly makmg sure 1t IS fully home and
res11ng agamst the stop protrud1ng from the base of the stub
duct. Ensure flue gas connectJng ducthas been cut to thecorrect
SIZe Seethe Flue KltlnstallatJon InstructiOns
(h) Reht thecollector hood making sure that the Hue duct sp1got
on the collectOr hood enters the flue duct connector. Tighten tl:e
twoconcctor hood r""ng screws Connect the gassupply pipe to
the apphance v1a a gas serviCe cock.
Note: The whole of the gas mstallaUon should be inspected and
tested lor soundness and purged in accordance with the
recommendations orBS 0891
(~ Flit he two chrome water fillings supplied using fibre wash e rs .
The fitting which Includes the stop valve should be fitted onto
the rear right hand connection (viewed from the front) and the
other fitting onto the rear left hand connecti on (viewed from the
front)
(j) F 1t the two copper tails supp lied to the chrome water fittings
llSing a JOinting compound su1tdb le lor use withpotable water.
(k) Connect the appliance to the incoming cold water supply via
theflttlng
which incl udes the stop valve
(I) Connect the apphance to the domestic hot water remote dr aw
orr points via theother fitting.
(m) At the bottom centre of the water section assembly there is
~n addltloMI 1 n m. ma le threaded jomt whiCh is the connecting
thread lor when aspout Is connected for an oversink installation.
See General information paragraph 2.10.
This outlet will not pa<s water until such t1me as an mtcgral tap
kn IS Installed on to the appliance and therefore. ma normal
remote draw off Installation, the 1 12 in. male threaded joint
should be left unconnected and unplugged
(n) 1\Jtn on the water supply to the apphance Open the stop
valve on the Inlet flttmg
to the appliance and then open the
hoghest hot watertap on theinstallation
Allow water tO pass 1n order tO vent the system Of aJt Close the
tap.
9. Commissioning
Before commossiOntng the apphance. the whole gas installation
must be purged and tested for gas soundness in accordance 'ovith
the current cd1uon orBS 689t
tmportan~ Open ,,II doors and w1ndows Extmgu1sh naked hghts
•nd do not smoke while purgmg the gas line.
(a) Ensure that the gas se rvice cock in the gas inlet pipe is
turned orr
(b) I.Ooscn screw A and connect a pressure gauge to the test
point. See Ftg 4.
(c) 1\.Jrn on the gas ""rvlce cock .
(d) Move the gas control sli de to the igni ti on position. Sec Fig. 5.
Observe thepilot burno1 through the observation wmdow. P re ss
in the cent re b utt on orthe co ntrol sli de and hold dep r essed while
pushing In the Ple1.o Igniter bu tton two or th r ee times. The pilot
7
Fig. 4. Inlet pressure test point
Front
should hght. waot 20 seconds and then release the centre button
of thecontrol slide.
The pilot should remain alight If the pilot Is not established.
repeat the operat1ons untilaflame IS established
Note: On initial light up. or after prolonged shut·down. the
establishment
of the pilot may take several attempts due to the
presence of alt In the gas supply p1pe
The p1lot name should envelope approximately s mm or the
thermocouple head .
(e) Move the control slide fu lly to the right See rig. 6. fUlly open
any ho t wa ter tap . The main burner sho uld light.
(0 Check the dynamic inlet gas pressure. The pressure for natural
gas should be 20 mbar and the pressure for LPG should be 37
mbar.
Fig. 5. Gas control slide - ignition position
Pie1o igniter
0 +
(---(
Gas COfttrol sfide in this pos1tion
Fig . 6. Gas control slide -operating position I
P 1e zo igniter
+
(---·--....(
Gas control sli de in this pos it io n

~ Fig. 7. Gas control slide - shut down position l
P~tzo ;gn~er
0
~
I
Gas cootiOI slide in this f)Ollhon
II the prtssure IS not correct then chtck the s•s supply to the
•ppllancc.
If tht p1essurc is correct, tum off the hot w~ter tap ~nd move the
control slide to the off pos1t10n. S.e rig. 7
i\ltn off the gas service cock Remove tht pressure gauge and
tighten screw A. see F1g 4
W Loo>en screw Dand connect a Pfts5Urt gauge to the test
point see FJ8. s
Re-light theapplianceas desa1bcd In p.uograph9 (dand el
(h) Operate the appllanu lc< at least 2 monutes then check that
the burner pressure is asstated In lKhnl':al Dat.a -Table 1
t•l 1\Jm off the hot water tap Clo•• th•gas <4'tv1Ce cock. Remove
the pressure gauge and tighten screw D
(I) Re·fltthe appliance casing using the four fixing screws. Fit the
plostic Temperature Control Knob housong f1t the Temperature
Control Knob. F1t the four casing screw cover•
tk) On completion of the commissioning and testing of the
sy<tem. the lllstaller should hand over th~ appliance to the user
w1th reference tothe followmg
t . Grve the users OperatmgtnstructJOns leo~Retto the user
2. Explam and demonstratt the liahtlng and shutdown
procedures
3 Advise the user of the precautions necessary to prevent
damage to the systtrn and to the buildang '" the event of
the sy<tem remamlllg anoperauve duttng frost conditions.
4 Stress the unportance of an annu•l service by a competent
heatmg engu>eer
Fig. 8. Gas pre ss ure test po i nt
8
10. Ins pe ction and Servicing
To tnsure conunued elhcl'nt operatiOn of the appliance. It 15
recommended that It as checked and seMCed as necessary at
regular Intervals.
The frequency of serviCing wall depend upon the ~rucular
anstallatlon conditiOns and u<age but m general once a year
should be adequate
It IS the law that any servKe work must be carried out by a
competent person such a' Bntlsh Gas or other COrgi regt~erod
per.annel
~!<!lore commenCing any sorviCe operatiOn turn ofl the gas
supply at the m.IUI ~ •me• cc ICk.
ACCESS FOR SERVICING
Remove the front casang by removmg the lour plastic screw
CC)V()tS and then remove the four fixing screws.
Pull off the Temperature control Knob.
Unscrew Temperature Co nar ol Knob housing.
Lift the casang clear
10.1 Heat exchanger
Remov• the collector hood assembly by slackemng the two
"'""""'8 sc~-s and pulbng the hood out ol the flue connector
cluct. IIthe connecto< duct comes away with the colleaor hood
separ<lle them and push theconnectorduct back into the st..t> In
the bdlanced ftue assembly mo~ldna sure that « is fuly home and
re<tmg agalllst the two stops PfOINd•ng from the Sides of the
stubduct
Inspect and clean the heat exchanger flueways if necess~ry
To remove the heat exchonger. Isolate the appliance from the
Incoming cold supply and drain down the appliance via the
drain cock fitted
Disconnect the heat exchanger flow and return pipes at the
water section and thebase of the combustion chamber.
Remove the locknuts from the heat exchanger stubs and lift the
heat exchangerclear
In hard water areas 1t may be necessary to descale the heat
exchanger body Eather a propnetary brand of descaler or a
solution of 10 parts of water to 1 part of hydrochlonc acad
•hould be used Ftll the heat exchanger w1th this soluuon and
leave untd the solutiOn stops bubbling. Dratn and thoroughly
woshout the exchanger wtth clean water.
Warning: Acid/water solutions must be used wath extreme
caut10n Take care not to splash on to the skill or into the r,oes
Wash any affected area> wllh larse amounts of cold ""ter and
<eek medacal adVICe
10.2 Pilot assembly
Inspect the palot InJectOr and clean dnecessary.
Check the p•lot burner and electrode are clean and undamdged
Cl ean or replace II necessary.
Pull off the pilot filter and clean .
10.3 Main burner
Disconnect the pilot gas pipe and thermocouple at the gas valve
and pull off the red cable from the P1ezo urut.
DISCOnnect the pilot gas ptpe from the pilot burner and r-
from the appbara complete ""ilh seal. Take care not tO lose the
polot "''ec:!O<
Remcrve the two scr ..... -s ,..alnifli the pilot bracket and lift the
complete assembly ~at
Undo the un10n connectiOn below the burner. Llft the burner
clearand remcrve
Inspect and clean the Injector> IInecessary.
Inspect and clean the main burner bars if necessary.
10.4 Slow ignition valve
screw out the slow lgnatton valve (which is located on the rtgh1
hand side of the valve above the water Row pipe 1nto ahe heat
exchanger Item 17 . Fig 1

The ball within the valve should move freely . Check by shaking .
Che<:k theO·ring and replace if necessary .
Re - assemble in reverse order .
1
0.5 Re-assembling the appliance
Re·assemble the appliance in reverse order ensuring the
follow ing :
1.
The collector hood outlet duct correctly enters the flue
connecting du ct.
2. The washer in the main gas line union connection is
correctly l ocated .
11 . Replacement of Parts
It is the law that any service work must be carried out by a
competent
person such as British Gas or other Corgi regist ered
personnel.
Before commencing any service operation turn off the gas
supp lyat the mam gas serv ice coc k.
11.1 Pilot burner /injec t or
Disconnect the pilot gas pipe and thermocouple at the gas valve
and pull off the red cable from the P iez ounit.
Disconnect the pilot gas pipe from the pilot burner and remove
from the appliance complete with seaL Take care not to lose the
pi lot injector Replace i njector if necessary .
Remove the two screws retaining the pilot bracket and lift the
complete assembly clear complete with the red seal.
Pull off the pilot filte r. Undo the screw fixing the spark electrode
/thermocouple re taining bar and lifi these clear.
Replace the pilot burner/bracket and re-assemble in rev erse
order.
11 .2 Spark el ectrode/th er mocouple
fallow
the instructions in Section 11 .1 and re p lace the fau lty
component.
11 .3 Ma in burner
Disconnect the pilot gas pipe and the rmoco up le at the gas valve
and pull off the red cable from the Piezo unit.
Discon nect the pilot gas pipe from the pilo t burner and remove
from the appliance complete with seal. Take care not to lose the
pilot inJeCtor.
Re move the two screws retaining the pilot bracket and lift the
complete assembly cl ear .
Undo the union connccrion below the burner . Lift t he burne r
clear of the un i on and push the f ro nt of the burner up tnto the
combustion chamber so that it is standing vertically against the
rear . Pull the rear of the burner forward so that the burner is now
upside down and work out between the combustion chamber
skirt
and gas pipe.
Replace the burner and re·assemble in reverse order taking care
that the seals around the igniter cable/thermocouple and pilot
gas pipe are correctly seated in the combustion chamber base
and thepilot injector has been fitted.
11 .4 Heatexchanger
Remove the collector hood assembly by slackening the two
retaining screws and pulling the hood out of the flue connector
3. The seals around the igniter cable/thermocouple and pilot
gas pipe are correctly seated in the combustion chamber
base and the piloti njecto r has been fitted.
Turn on the gas supply at the main gas service cock and check
for gas soundness in accordance with the current edition of BS
6891 while the appliance is running.
Re · commission the appliance as detailed in section 9.
duct. If the flue connector duct comes away with the collector
hood , separate them and push the connector duct bac k into the
stub in
the balanced flue assembly making sure that it is fully
home and resting against t he two stops protruding f rom the
sides ofthestub duct.
Isolate the app lian ce from the incoming cold water supply and
drain down the appliance via the fitted drain cock .
Disconnect t
he heat exchanger inlet and outlet pipes at the
water section and at the base of the combustion chamber.
Remove the locknuts from the heat ex changer stubs and lift the
heat exchanger clear .
Replace the heat exchange r and re-assemble in reverse order .
11. 5 Piezo un it
Pull off t he two wires from the rear of t he un it, unscrew the
pl
astic retaining nut on the control panel and push outthe Piezo
unit.
Replace and re · assemble in reverse order .
11.6 Wa ter section
Isolate the appliance from the mcoming cold water supply and
drain down the appliance via the fitteddrain cock.
Disconnect the four union connections .
Release the two screws between t he water section and gas
section and pull the water sec tion clear .
The di aphragm within the valve can be replaced by removing the
three fiXi ng screws holding the va lvebody together .
The water filter fitted into the incoming cold water tapping can
be cleaned or replaced by pulhng itout.
Re ·a ssemb1e in reverse order.
11 .7 Gas va lv e
Remove the water section as described in Sect i on 11 . 6.
Disconnect the pilot gas ptpe and thermocouple from the gas
valve.
Pull off the two cables from the rear of the Pi ezo unit.
Re lease the main gas pipe union connection below the
combust i on chamber and lift the va lve clear complete with the
control panel.
Remove the Plezo unit as described in Section 11.5.
Remove the control facia by taking out the fou r fixi ng screws and
lifti ng clear comp l ete with slider knob.
Prise out the slider bar and remove the two screws re taining the
control frame and lifi clear .
Replace the gas valve and re-a ssemb le in reverse order.

12. FaultFinding
Problem Cause Solution
Incorrect water temperature Incorrect
gas rate Check thegas supply to appliance gas servoce cock
Open the gas semcecock
Ch«k thebutner pressure
Check the inlet pressure
Water scct•on slicking or faulty Clean or replace
Incorrect water flow rate
Incoming supply valve closed
Open supply valve
Low water pressure Check the water pressure is above 0.1 bar
Water sec tio n slicking or faulty Clean or replace
Noise Sca le In heat exchanger Descale and service
High gas rate Check the burner p ressure
Low waterflow rate Check thewater flow rate
Pliot flame will not stay aUght No gas supply
Connect gas supply
Gas sei'VIce cock closed
Open gassemcecock
Air In gas hne Purse the bne
Pilot InJectOr blocked
dean/replacethe mje<:tor
No spark Clean or replace the electrode. Piezo unit or cable
Main burner will not light Gas pressure low Check the inlet and burner pressure
Gas servi ce cock partially closed
Open thegas service cock
LOw water rate Ch
ec k the water rate
Water sec tion diap hrag mfaul ty Repla ce the diaph rag m
Gas va l ve faulty Rep l ace th egasval ve
Explosive 1gniUon Reduced pliot flame Clea n or replace the pilot in j ector assembl y
Faulty slow igmtion valve Replace the slow igni tion valve
13. Short Parts List
Part Manufacturer's Reference
Pilot Burner 8 7
18 lOS 048
Pilot Injector 8 708
200005
Thennoeouole g 707 202039
Spark Electrode 8 708 107 002
Piezo Unit 8 748 108 023
Water Secuon 8 707 002 457
Diaohra!lrn 8 700 503 051
Slow Ignition Valve 8 708 503 063
Gas Valve 8 707 0
11 028
Temf)erature Control Kn ob 8 702 000
111
Control Fa c in Plate 8 70 1000 1
04

Additional Information
1. CE Certification
MODEL WR325·1AD ...
I
WR32S ·I AV ...
CENUMBER
CE0085 AQ 0293
CATEGOR IES
(2H
I
"·
TYPE c.,
2. Symbols on Data Plate
Pn Nom ina lu se ful output
P min Minimum usefuloutput
On Nomina lhe at input
Q...., Mrmm um heat input
Pw Maximum service water pressure
P......, Minimum servicewaterpressure
"!Ype: C11 • Natural draughtappliances
11

~~~ORCESTER
Bosch Thermotechnik
WOrctSllf<f Htot Systems Lnr.tted.Couwofd Woy. \o\'omdon. Ylort"tsttr WR4 951-'1.
Te/<-phor.t j0190SJ75462<f. Fox: (OJ90SJ 754619
Th is bookle t is accu ra teat thed ate of pnn1ing b~ll wlll be supctscdcd and shou ld be di sregarded If spec: ifl cotlo nsrmd/or appearances are changed in the i nte1e su
of continued imp ro vement.
Al l goods so ld t1 1C 3ubjCCl to our official Conditions ol Sal e, acopy of which mav be obtained onapplication.
P U8 1,1 CA: ri0N 6 720 6034 94. 1 SSUE I • SEPTEMBeR 200 I